Currently the server-timing header only expose the cache status (hit, miss, pass, etc.).
In order to restore the ability to collect per-host data in the navtiming daemon, we need a way for the client code to know which DC/host served the request to them.
This can be achieved by extending the contents of the server-timing header to also include the name of the cache host that served the request.
For example, instead of this:
We could serve this:
server-timing: cache;desc="pass", host;desc="cp3056"
We used to get this information for free in the old EventLogging pipeline, because event.gif was served from the same edge cache host as the rest of the requests, but that's not the case anymore with EventGate.